Electrosurgical knife is an important instrument for electrically cutting and coagulating, which is widely used in surgical operation. In comparison with traditional surgical knife, the electrosurgical knife has the advantage of less blood loss and higher efficiency, and becomes an indispensable instrument for most surgeons. However, during the procedures of dissection (electrical cutting) and/or blood coagulation (electrical coagulation) by means of electrosurgical knife, smokes are generally generated, impairing the field of vision of the surgeon. In addition, blood and debris produced during surgical operation also obstruct the operation. For removing the smokes, blood and debris, a suction device is necessary to follow the movement of the knife synchronously.
Originally, the electrosurgical knife and the suction device are separated from each other, but in this way, both hands of a surgeon are occupied. Alternatively, two practitioners are needed for operation, causing much troubles in surgery operation. Moreover, application of separate suction device brings difficulties in precise positioning of surgical operation. Consequently, dissectors having both the electrosurgical knife and the suction device and thereby having functions of cutting, suction and coagulation simultaneously, was provided, for example, in U.S. Pat. Nos. 5,071,418, 5,246,440, 5,318,565 and 5,413,575.
Although different surgical dissectors have been disclosed in the above-said U.S. patents, all of them have the disadvantages of complication, bulk and inconvenience. It is important that each of these dissectors comprise a knife portion and a suction portion, with the knife portion performing electrical cutting and coagulating, and the suction portion performing suction. In this way, the functions of electrosurgical knife and suction device are rather limited, and the suction device can not be utilized efficiently.